1. Field of the Invention
This invention relates to an ink jet recording apparatus which is applicable to various printers, and printer portions to be applied to various instruments.
2. Related Background Art
This kind of apparatus is equipped with a constitution inherent in the system which performs recording by discharging ink other than the constitution concerned with direct recording.
More specifically, corresponding to the recording data, when no discharging is performed at the discharge port or when the apparatus itself is not used for a long term, the ink at the discharge port or within the ink liquid chamber communicated to the discharge port may be sometimes increased in viscosity to cause non-discharging. Also, ink liquid droplets, water droplets or dust, etc. may be deposited on the discharge port surface where the discharge port is arranged, whereby the ink liquid droplets may be sometimes drawn by these deposits to be deflected from the discharging direction. For this reason, the ink jet recording apparatus is equipped with various constitutions as the so called discharging recovery system for preventing previously non-discharging or deflection of the discharging direction.
As these recovery systems, for the constitution which prevents non-discharging, there is preliminary discharging which removes ink which is increased in viscosity, etc. by discharging ink onto a predetermined ink receiving medium, ink suction which performs the above-mentioned removing operation by sucking ink from the discharge port or the ink liquid chamber, and further capping which prevents ink solvent evaporation from the discharge port by closing the discharge port surface.
Also, for the constitution to prevent deflection of the discharging direction, there is a constitution which wipes the discharge port surface, thereby removing dust, ink liquid droplets, etc. deposited in the vicinity of the discharge port.
On the other hand, in the ink jet recording apparatus, particularly recording heads in recent years, preparation is now performed by film forming steps of semiconductors or microworking techniques, whereby smaller and less expensive recording heads are going to be realized. Also, recording heads of the disposable type, for example, integrated with an ink tank have been proposed.
As the result, it has been desired to provide an ink jet recording apparatus which can be used handily by users by making the apparatus itself small in scale and low in cost.
Whereas, for realizing the ink jet recording apparatus as described above, particularly the apparatus which is of small scale and low cost, and further is the disposable type, there are various tasks to be solved.
These tasks exist primarily in the constitution for discharge recovery as described above, and miniaturization of the apparatus is hampered by preliminary discharging, ink suction, and further the space for arranging the apparatus for capping. Also, miniaturization of the apparatus is also hampered by the space for the waste ink tank for storing waste ink deposited by preliminary discharging or suction, and the suction pump, tube, etc. for leading waste ink thereto.
Of the constitutions of the above-mentioned recovery systems, particularly in the constitution of performing capping, it has been practiced in the prior art to use the cap for preventing ink evaporation by closing the discharge port from the air with the cap to be used for sucking ink from the discharge port for eliminating clogging, etc.
For this reason, ink solvent is evaporated from the tube to be communicated to the suction pump or these connecting portions, etc., whereby there was a problem that insufficient suction after closing with the cap resulted.
The constitutions of the above-mentioned recovery systems, particularly the constitution comprising storing waste ink absorbed proposed in the prior art, include the constitution in which a waste ink tank is provided at a predetermined position of the apparatus and waste ink is discharged there, the constitution in which a plate-shaped ink absorbing member is disposed internally of the apparatus and waste ink is discharged there to promote evaporation, and further the constitution in which these ink absorbing members are made replaceable.
However, according to the constitutions as described above of the prior art, the space for a waste ink tank or ink absorbing member must be ensured, whereby there was a problem that the apparatus became enlarged.
Also, there has been known in the prior art a constitution in which waste ink is recovered into an absorber provided in a separate chamber of an ink cartridge. However, since this constitution is a constitution in which ink is collected by inserting the needle at a tube tip end for guiding waste ink into the rubber cap of the cartridge, the absorbing ability of the whole absorber could not be taken advantage of, and consequently it could not be utilized except for the disposable type.
Also, in the recovery system, since the connection tube from the cap to the pump, the drain tube from the pump to the waste ink tank are required, the constitutions of these apparatuses become complicated, and also there was involved the problem that the space for arrangement of the tubes was necessary.
Also, due to the presence of the tubes, evaporation of ink solvent from the tubes increased, whereby the ink within the tube or in the vicinity of the discharge port increased in viscosity, until it was finally deposited.
Further, since a one-directional valve is provided on the piston shaft, a certain area is required for the piston shaft end for the arrangement portion thereof. For this reason, the diameter of the piston becomes greater, which led to the problem that the pump itself became larger. Also, in this pump, since the load on the solid rubber generally used for formation of the main piston is great relative to deformation, the actuation force of the piston became nonuniform, whereby stable suction actuation could not be performed in some cases. Also, the piston of solid rubber is poor in durability, having poor resistance to dust, etc. which can be brought in by suction, whereby the suction effect may be sometimes markedly lowered.
Also, as shown in Japanese Laid-open Patent Applications No. 59-14964, No. 59-45161, there has been proposed a constitution of the system in which a blade portion such as rubber, etc. and a non-absorptive cap portion are provided in the circumferential direction and rotated while discharging ink. However, when the ink removed from the head with the blade is attached at the root in the vicinity of the blade, such ink, etc. cannot be removed even with the cleaning member arranged for cleaning the circumferential surface, which consequently caused the capping itself to be unstable or the cleaning effect to be deteriorated.
Anyway, none of the recovery means of the ink jet recording apparatus improved this operation when they are miniaturized.